Signs, Sigils, Glyphs, & Marks

A sign is a persistent, powerful symbol marked on an inanimate, stationary object.

A sigil is a sign marked on an object that can be moved, including a living creature.

A glyph is a sign that can only be used once and is consumed.

A mark is a glyph that can move, including one on a living creature.

All of the above are runes of different types.

Sigils are often used as concealed weapons. An assassin with a powerful sigil can conceal the symbols underneath a glove, revealing them in time to touch a target and impart whatever spell is attached to the sigil. Marks are used likewise, and come with the added benefit of eliminating themselves as evidence on use, leaving behind nothing but a magical signature.